The need for implants for repairing tissue defects, such as cartilage tissue defects, is ongoing. Materials have been developed to fill spaces comprising tissue defects, but have typically been two-dimensional, comprising, for example, a flat sheet cut to approximate the dimensions of a tissue defect, or a layer of cells grown in vitro, from which a two dimensional sheet of cells is applied to a tissue defect.
U.S. Pat. No. 5,067,964 to Richmond et al. discloses an articular cartilage repair piece and methods of forming. This patent discloses a repair piece which includes a backing layer of non-woven, felted fibrous material which is conformable to flat and curved surfaces.
U.S. Pat. Nos. 5,655,546 and 6,179,871 to Halpern disclose methods for repairing a cartilage defect, comprising the provision of apertures in the cartilage by drilling holes at the base of the cartilage defect. The holes may enter the mesenchymal depot. In these methods, a porous scaffold material containing a plurality of magnetic particles is introduced into the apertures. Subsequently and sequentially, magnetically-tagged cartilage growth promoting materials such as chondrocytes or growth factors are injected into the area of the defect.
U.S. Pat. No. 6,443,988 to Felt et al. discloses methods and apparatuses for repairing a tissue site. The method involves use of a curable polyurethane adapted to be mixed at time of use in order to provide a flowable composition and initiate cure.
U.S. Pat. Nos. 6,511,958 and 6,514,514 to Atkinson et al. disclose devices and products for repair of cartilage lesions, comprising a cartilage repair matrix suitable for conforming to a cartilage defect and a cartilage-inducing composition on or within the matrix.
U.S. Pat. Nos. 6,626,945, 6,632,246 and 6,852,125 to Simon et al describe cartilage plugs made from a biocompatible artificial material. These plugs are made according to pre-determined shapes.